Connective Tissue Flashcards Preview

ESA 1 - Body Logistics > Connective Tissue > Flashcards

Flashcards in Connective Tissue Deck (18):
1

What are the 4 basic types of tissue?

1. Nervous
2. Epithelial
3. Muscle
4. Connective

2

What are the types of CT?

1. Proper

Specialised
2. Adipose
3. Blood
4. Bone
5. Cartilage
6. Haemopoietic (bone marrow and lymphoid)

3

What cells does CT arise from?

Mesenchymal stem cells

4

Suggest 6 functions of CT?

1. Connects cells to form tissues, tissues to form organs and organs to form the body. Some CT provides support (cartilage/bone).
2. Transport: medium for diffusion of nutrients and wastes.
3. Protection: cushion between tissues and organs, and insulation (adipose).
4. Storage (adipose).
5. Defence against infection (blood/lymph/fixed and wandering cells)
6. Wound healing (macrophages, fibroblasts, myofibroblasts).

5

What are the 3 general components of CT proper?

1. Cells
2. Fibres
3. Ground substance

6

Which cells secrete the fibres (collagen) and ground substance of CT?

Fibroblasts

7

As well as producing CT, what is an important role of fibroblasts?

- Wound healing
- Scar tissue formation - myofibroblasts = modified fibroblasts containing actin. Responsible for wound contraction when tissue loss has occurred.

8

What are the 3 types of fibres in CT and why are these important?

1. Collagen - flexible with high tensile strength
2. Reticular - provide a supporting framework
3. Elastin - allows tissue to recoil after stretch

9

What is the most common protein in our body?

- Collagen
- 1/4-1/3 of whole-body protein content

10

How many types of collagen do we have and which is the most common?

- 28
- Type I (90% of all collagen)

11

What is the difference between type I, II, III & IV collagen?

- Type I: fibrils (composed of alpha chain triple helix) aggregate into fibres and fibre bundles (e.g. tendons, organ capsules and skin dermis).
- Type II: fibrils do not form fibres (e.g. hyaline and elastic cartilage).
- Type III: fibrils form fibrils around muscle and nerve cells and within lymphatic tissues and organs - reticulin.
- Type IV: unique form present in basal lamina of basement membranes.

12

What are reticular fibres and where are they primarily found?

- Consist of type III collagen.
- Form an irregular anastomosing network throughout lymph nodes, with lymphocytes densely packed in the spaces between the fibres.

13

What are elastic fibres composed of?

- Primary component = elastin.
- Enfolds and is surrounded by fibrillin microfibrils.

14

Where are elastin fibres found?

- Occur in most CT but to widely varying degrees.
- Important role in:
~ dermis
~ artery walls (allows stretch and recoil)
~ lungs
~ elastic cartilage

15

Which disease is associated with abnormal elastic fibres?

- Marfan's syndrome
- Autosomal dominant - abnormal expression of fibrillin gene
- Abnormally tall, arachnodactyly, frequent joint dislocation, risk of aortic rupture.

16

What is the ground substance of CT made up of?

- Proteoglycans = large macromolecules consisting of a core protein to which glycosaminoglycans (GAGs) are bound.
- High water content - viscous.

17

Why does ground substance have a high water content?

GAGs attract water as they are:
- strongly hydrophilic
- highly negatively charged - attract cations (e.g. sodium ions), causing water to be sucked into the matrix

18

Describe the properties of a unique GAG.

- Hyaluronic acid
- Bound to proteoglycans by a linker protein - forms giant hydrophilic macromolecules.
- Present in ground surface of cartilage - allows it to resist compression without inhibiting flexibility.